CWE-395

Base Abstraction Level
Pillar — Highest-level weakness category
Class — Abstract, language-independent
Base — Specific enough to detect
Variant — Tied to specific technology
Compound — Requires multiple weaknesses Draft MITRE CWE Status
Stable — Fully reviewed and complete
Draft — Under development, may change
Incomplete — Partially defined by MITRE
Deprecated — No longer recommended
Obsolete — Replaced by another CWE
Use of NullPointerException Catch to Detect NULL Pointer Dereference

Description

Catching NullPointerException should not be used as an alternative to programmatic checks to prevent dereferencing a null pointer.

Programmers typically catch NullPointerException under three circumstances: The program contains a null pointer dereference. Catching the resulting exception was easier than fixing the underlying problem. The program explicitly throws a NullPointerException to signal an error condition. The code is part of a test harness that supplies unexpected input to the classes under test. Of these three circumstances, only the last is acceptable.

Consequences

Availability — DoS: Resource Consumption (CPU)

Mitigations

Phase: Architecture and Design, Implementation

Do not extensively rely on catching exceptions (especially for validating user input) to handle errors. Handling exceptions can decrease the performance of an application.

Detection

Automated Static Analysis - Binary or Bytecode

According to SOAR [REF-1479], the following detection techniques may be useful: Cost effective for partial coverage: Bytecode Weakness Analysis - including disassembler + source code weakness analysis Binary Weakness Analysis - including disassembler + source code weakness analysis

Dynamic Analysis with Manual Results Interpretation

According to SOAR [REF-1479], the following detection techniques may be useful: Cost effective for partial coverage: Framework-based Fuzzer

Manual Static Analysis - Source Code

According to SOAR [REF-1479], the following detection techniques may be useful: Cost effective for partial coverage: Manual Source Code Review (not inspections)

Automated Static Analysis - Source Code

According to SOAR [REF-1479], the following detection techniques may be useful: Highly cost effective: Source code Weakness Analyzer Context-configured Source Code Weakness Analyzer

Architecture or Design Review

According to SOAR [REF-1479], the following detection techniques may be useful: Highly cost effective: Formal Methods / Correct-By-Construction Cost effective for partial coverage: Inspection (IEEE 1028 standard) (can apply to requirements, design, source code, etc.)